MP 1.3.40 and 1.3.41 Antenna Tracker screen greyed out

I updated to MP 1.3.41 only to find the Optional Hardware - Antenna Tracker screen was greyed out and could not be accessed. MP 1.3.40 had the same problem. MP 1.3.39 had the old Antenna Tracker screen which worked ok. Hopefully there are no compatibility issues between MP 1.3.39 and AP 3.7.0.